Open-end spinning device and process for temporary receiving of a yarn by means of such an open end spinning device

ABSTRACT

In open-end spinning and in coordination with predetermined operating phases, a yarn suction pipe  3  by means of which a yarn F extending from a bobbin  121  is to be received temporarily is brought successively into different operating planes E a , E b  in which the yarn suction pipe  3  is imparted a defined operational movement in function of the operating planes E a , E b  occupied and in coordination with the current operating phase. The operating positions  3   b,    3   c  of the yarn suction pipe  3  that can be moved into at least two operating planes E a , E b  are defined in such manner that when the yarn suction pipe  3  is in its operating position  3   b,    3   c  in a first operating plane E a , a yarn F extending from the bobbin  121  pressing on winding roller  120  to the yarn suction pipe  3  crosses the traversing range of the yarn traversing guide  126  but is outside the traversing range of this yarn traversing guide  126  when the yarn suction pipe  3  assumes its operating position  3 A in an additional operating plane E b . The yarn suction pipe  3  is mounted on a swivel pin that is in turn mounted on an additional swivel pin.

[0001] The present invention relates to an open-end spinning device asin the introductory clause of claim 1 as well as to a process fortemporary receiving of a yarn by means of such a device.

[0002] With open-end spinning devices it is normal practice to have aservice unit patrolling alongside a plurality of identical open-endspinning devices so as to be able to perform maintenance tasks at eachone of these open-end spinning machines when necessary. For this purposethe service unit is as a rule provided among other things with a yarnsuction pipe that can be brought from a rest position within thecontours of the service unit into a work position in which it is locatedin close proximity of the yarn path (DE 196 34 300 A1). This yarnsuction pipe has e.g. the task to prepare a length of yarn for thepiecing return feeding and to temporarily store a yarn excess producedduring piecing, until it is used up due to the difference in speedsbetween a device drawing the pieced yarn from the spinning element andthe bobbin.

[0003] It is the object of the present invention to develop the knowndevice further in such manner, and to create a process for temporaryreceiving of a yarn by means of such a device, that it becomes possibleto handle beyond this additional tasks postponed in time.

[0004] This object is attained through the invention through thecharacteristics of claim 1. Due to the fact that the yarn suction pipecan be moved not only within one single operating plane but can bebrought out of it and into at least one additional operating plane, andcan be moved within that plane, the yarn suction pipe is capable ofcarrying out tasks in a further operating plane offset in time relativeto tasks to be carried out in a first operating plane.

[0005] Preferably the operating planes, of which at least two areprovided, of the yarn suction pipe are placed at an angle relative toeach other according to claim 2, so that they form an angle betweenthem. By “angle” an angle value is understood here, that is greater thanzero and smaller than infinite.

[0006] In a further development according to the invention of the todevice, the rest position of the yarn suction pipe is preferablydetermined as indicated by claim 3 and/or 4. This results inspace-saving advantages.

[0007] Preferably the operating positions are established in twooperating planes according to claim 5. This makes a soft transfer of theyarn to a traversing guide possible in one operating plane when the fullbobbin is set on the winding roller, while in the other operating planethe yarn extending from the yarn guide to the bobbin driven by thewinding roller is not within the traversing range of the traversingguide.

[0008] In an inventive further development of the open-end spinningdevice, it is possible according to claim 6 and/or 7 (35, page 2.)

[0009] The operating positions are preferably determined in twooperating planes according to claim 5. This makes it possible wheninstalling the full bobbin on the winding roller for a soft transfer ofthe yarn to a traversing guide to be carried out in one operating plane,while the yarn extending from the yarn guide to the bobbin driven by thewinding roller is not within the traversing range of the traversingguide in the other operating planes.

[0010] In a further development according to the invention of theopen-end spinning device, the yarn suction pipe can be controlled by acontrol device in accordance with a previously prepared programaccording to claim 6 and/or 7 so that it is taken into one of theoperating planes provided to carry out the operating movements thereinprovided for that operating plane.

[0011] For various tasks to be carried out by the yarn suction pipe itsuffices if it can merely be taken from its rest position into onesingle operating position; however in order for the yarn suction pipe tobe able to handle also more complex tasks, it is an advantage if theyarn suction pipe is also able to assume several operating positions oneafter the other in at least one of its operating planes, according toclaim 8.

[0012] In the interest of a simple design of the object of the inventionthe yarn suction pipe can be mounted on a swivel pin so that it can beswiveled, according to claim 9.

[0013] The movement of the yarn suction pipe from one operating plane toanother operating plane can be effected in various ways, e.g. by movingit along a guiding system. In a preferred embodiment of the deviceaccording to the invention it is possible to provide for the yarnsuction pipe according to claim 10 to be movable along its swivel pinor, according to claim 11, around an additional swivel pin supportingthe swivel pin of the yarn suction pipe into the additional, or one ofthe additional operating planes, it being advantageous to install thisadditional swivel pin according to claim 12.

[0014] The apparatus described above makes it possible to carry out aprocess according to the invention in adaptation to different operatingphases of the operating process whereby, according to claim 13, the yarnsuction pipe is brought into the corresponding operating plane in asynchronized manner, in which it then carries out its operatingmovements provided for this operating plane and this operating phase. Inthis manner the yarn suction pipe can carry out operating movementsdifferent from each other one after the other at different locations,and can thus carry out completely different tasks.

[0015] In another variant of the process according to claim 14 the of ayarn extending from the bobbin located in the spinning device or fromanother bobbin which may be located e.g. in a service unit containingthe yarn suction pipe to the yarn suction pipe, is received preferablyindependently of the tasks that the yarn suction pipe must carry outsubsequently, always in one and the same operating plane.

[0016] According to claim 15 and/or 16 and according to the invention,the yarn suction pipe can execute the operating movements required forthe formation of a piecing reserve or for the temporary storing of ayarn surplus occurring briefly during piecing in the same plane in whichit had previously taken up the yarn presented to it. In an advantageousfurther development of the process according to the invention and inaccordance with claim 17, the yarn suction pipe, upon having taken upthe yarn in one of its operating planes, can also be transferred intoanother operating plane where as a result of its operating movement itthen causes the yarn to be laid at one end of a full bobbin during theformation of yarn reserve. Such a yarn reserve is in that case formedpreferably in accordance with claim 18.

[0017] The device as well as the process according to the presentinvention makes it easily possible for one and the same yarn suctionpipe to carry out entirely different tasks at different times. At thesame time the design of the device is simple and space-saving, sinceinstead of a plurality of yarn suction pipes with the appertainingterminals and their controls, only one single such yarn suction pipe isrequired for a number of different tasks.

[0018] Examples of embodiments of the invention are explained belowthrough drawings.

[0019]FIG. 1 shows a schematic lateral view of a device according to theinvention with a yarn suction pipe that can be placed at will in one oftwo operating planes;

[0020]FIG. 2 shows a top view of a bobbin and of a yarn suction pipeinteracting with it;

[0021]FIG. 3 shows a lateral view of a controlled yarn suction pipeaccording to the invention together with its drives and a controldevice; and

[0022]FIG. 4 shows a modified embodiment of the driving apparatus of theyarn suction pipe.

[0023]FIG. 1 schematically shows an open-end spinning machine 1indicated by a broken line on the left side of the drawing, while aservice unit 2 is indicated on the right side of the drawing by means ofa dot-dash line and is able to patrol in a known manner alongside theopen-end spinning machine 1 that has a plurality of identical open-endspinning devices 10. Of the open-end spinning machine 1 as well as ofthe service unit 2, only those elements that are necessary to understandthe invention are shown in the FIGS. 1 to 4. For this reason only aknown yarn suction pipe 100 of an open-end spinning device 10 of thistype is shown in FIG. 1.

[0024] The open-end spinning machine 1 is furthermore equipped with ayarn draw-off device 11 with a draw-off shaft 110 which extends over aplurality of identical, adjoining openend spinning devices 10. Duringthe drawing off of a yarn F from the open-end spinning devices 10 apressure roller 111 presses against this draw-off shaft 110 and can belifted off from the draw-off shaft 110 when necessary.

[0025] The yarn F drawn off by the yarn draw-off device 11 from theopen-end spinning devices 10 is conveyed to a winding device 12 equippedwith a winding roller 120 that also extends over a plurality ofadjoining open-end spinning devices 10, on which a bobbin 121 liesduring the spinning process in order to wind up the yarn F produced inthe open-end spinning device 10. The bobbin 121 is held in a knownmanner between two bobbin arms 122 and 123 (see FIG. 2) by means ofrotatably mounted bobbin plates (not shown), whereby the bobbin arm 122has a lifting arm 124.

[0026] During the spinning process the yarn F is traversed by a yarntraversing guide 126 located before the bobbin 121 as seen in thedirection of yarn movement (see arrow f₁), so that the yarn F is laiddown evenly over the length of the bobbin 121 (bobbin body) duringwinding. To ensure nearly constant yarn tension of the yarn F duringthis operation, a yarn tension equalization hoop 127 is installed withinthe course of the yarn before the yarn-traversing guide 126 in thedirection of draw-off (see arrow f1).

[0027] A swiveling suction pipe 20 is located on the service unit 2 andcan be swiveled from the shown rest position until it is in proximity ofthe bobbin 121.

[0028] In addition a presentation device 21 that can be brought from alower end position 21 a indicated by a full line into an upper endposition 21 b by swiveling around a swivel pin 210 is installed on theservice unit 2. This presentation device 21 has a swiveling yarn catcher211 at its free end.

[0029] In proximity of the swiveling range of the yarn catcher 211 is acontrollable clamping device 220 which is part of a yarn feeder 22. Thisyarn feeder 22 can be brought from a starting position indicated by afull line into a second position 22 a above the outlet opening 101 ofthe yarn draw-off pipe 100.

[0030] In the area of the lower end position of the presentation device21 is a yarn end preparation device 23.

[0031] The service unit 2 is further equipped with an auxiliary rollerpair 24 with a stationary roller 240 across from the service unit 2 anda driven roller 241 which can be presented to the roller 240.

[0032] In addition a reserve hoop 25 by means of which a piecing reserveA can be constituted and which swivels around a swivel pin 250 islocated on the service unit 2

[0033] In addition a yarn suction pipe 3 of which FIG. 1 only shows thearea with its outlet 32 is provided on the service unit 2. This yarnsuction pipe 3 is mounted on a pin 40 so as to be able to swivel (seeFIG. 3) and can execute operating movements as desired within a firstplane E_(a) or a second operating plane E_(b) or can be moved intodifferent operating positions 3 b, 3 c or positions 3A, 3B, 3C (see FIG.2). The yarn suction device 3 is connected to a hose 31 that is in turnconnected to a negative-pressure source in a controllable manner notshown here.

[0034] As a comparison between FIGS. 1 and 2 shows, it is not importantwither a cylindrical or conical bobbin 121 is being formed; thedescribed device and also the described process can be appliedindependently of the shape of the bobbin 121 being formed.

[0035] The structure of the device was described above, and now itsoperation during piecing following stoppage of the open-end spinningdevice 10 shall be described with the help of FIG. 1. For example a yarnbreakage has occurred, and the bobbin 121 has therefore been lifted fromthe winding roller 120 by raising the lifting arm 124 (FIG. 2) and hasthus been stopped.

[0036] In order to resume the spinning process, a piecing process mustbe carried out. For this the suction pipe 20 is first swiveled from itsrest position shown in FIG. 1 towards the bobbin 121. Furthermore anauxiliary drive roller (not shown) is brought to bear on the bobbin 121,by means of which the bobbin 121 is driven in unwinding direction (arrowf₃). Because of the negative pressure prevailing in the suction pipe 20,this suction pipe 20 takes up the yarn end located on the bobbin 121 andsucks it up to the extent that it becomes available through the reverserotation of the bobbin 121. As soon as the suction pipe 20 has taken upa long enough yarn segment to ensure secure holding of the yarn F, thesuction pipe 20 is swiveled back into its starting position while thebobbin 121 is at first still driven in unwinding direction (see arrowf₃), so that the suction pipe 20 continues to take up the length of yarnreleased by the bobbin 121 until the bobbin 121 is stopped by stoppingthe (not shown) auxiliary drive roller.

[0037] The yarn suction pipe 3 that has been until then in its restposition 3 a in a first operating plane E_(a) (see FIGS. 1 and 2) isbrought within this first operating plane E_(a) with its outlet 32 intothe operating position 3 b shown in FIG. 1 by swiveling it around itspin 40. In this position the yarn F passes the zone of the outlet 32 ofthis yarn suction pipe 3 during the further operating phases, as shallbe explained further below.

[0038] By means of the (not shown) auxiliary drive roller the bobbin 121is driven in winding direction (arrow f₂) for a short time. Since thebobbin 121 is in lifted position and the yarn F connected to the bobbin121 extends to the suction pipe 20, the path of the yarn does not crossthe movement range of the yarn traversing guide 126. Thereby parallelwindings are produced on the bobbin 121 and these are located at adefined location relative to the longitudinal extension of the bobbin121 due to a corresponding (not shown) configuration of the outlet ofthe suction pipe 20. A defined yarn path results in this case betweenthe bobbin 121 and the suction pipe 20.

[0039] At the latest at that point in time, the presentation device 21is swiveled around its swivel pin 210 from its lower end position 21 ainto its upper end position 21 b, whereby the swiveling path of thepresentation device 21 is located outside the path of yarn F extendingfrom the bobbin 121 to the suction pipe 20. When the presentation device21 is in its upper end position 21 b the yarn catcher 211 located at thefree end of the presentation device 21 is actuated and is moved intosuch a position that it seizes and takes along the yarn F during thefollowing downward swiveling motion of the presentation device 21, sothat this yarn F forms a loop (not shown) between the bobbin 121 and thesuction pipe 20. The length of yarn necessary for the formation of theloop is withdrawn from the suction pipe 20 in this process.

[0040] As the presentation device 21 is swiveled down into its lower endposition 21B, the yarn F reaches the nip of the clamping arrangement 220of the yarn presenter 22, where it is fixed by clamping. At its leadingend relative to the down-swiveling movement the presentation device 21is supporting a yarn cutting device (not shown) that is now actuated.The yarn segment freed thereby and extending to the suction pipe 20 isremoved through the suction pipe 20.

[0041] The presentation device 21 continues its down-swiveling movementand takes the yarn end produced by cutting into the zone of influence ofthe yarn end preparation device 23 where it releases the yarn end. Theyarn end is now held by the yarn end preparation device 23 that puts theyarn end in a known manner into a state that is suitable for the piecingprocess to be carried out.

[0042] The bobbin 121 is now driven by means of the (not shown)auxiliary drive roller in unwinding direction (arrow f₃), whereby theyarn length freed thereby from the bobbin 121 is taken up by the yarnsuction pipe 3 which had already been brought into the path of the yarnas described earlier. When the yarn segment stored in the yarn suctionpipe 3 has reached a predetermined length, a piecing reserve A isconstituted by swiveling the reserve hoop 25. The length of yarnrequired for this is taken from the yarn suction pipe 3.

[0043] The yarn presenter 22 is then taken out of its starting positionindicated by a full line into its position 22 a in which the free yarnend is within the area of influence of the air stream entering theoutlet opening 101 of the yarn draw-off pipe 100. This air stream isproduced in a known manner inside the open-end spinning device. The yarnsuction pipe 3 brought into the path of the yarn compensates fordifferences in yarn length that occur in this case.

[0044] During the movement of the yarn presenter 22 into its position 22a, the yarn F comes into contact with the roller 240 of the auxiliaryroller pair 24. The second roller 241 is now applied on the roller 240so that the yarn F is in the nip of this auxiliary roller pair 24.

[0045] The release of the lifting arm 124 causes the bobbin 121 to belowered so that it is again applied to the winding roller 120 and sothat the bobbin 121 is again driven in the winding direction (arrow f₂),thus winding up the yarn F drawn as a result of this from the yarnsuction pipe 3. The driving of the bobbin 121 can at first be assistedalso by the (not shown) auxiliary drive roller that continues to beapplied to the bobbin 121.

[0046] Before the lowering of the bobbin 121 on the winding roller 120,the yarn F extending from the bobbin 121 to the yarn suction pipe waslocated above the yarn tension equalization hoop 127 and also outsidethe movement range of the yarn-traversing guide 126. However thelowering of the bobbin 121 causes the yarn F to enter this movementrange and crosses the movement path of the yarn-traversing guide 126.The latter thus receives the yarn F and forms windings crossing eachother on the bobbin 121 as the yarn is wound up on it. At this point intime the yarn F is not yet within range of the yarn tension equalizationhoop 127, nor is this necessary, since the bobbin 121 is able to drawoff the yarn length needed for winding from the yarn suction pipe 3without change of the yarn tension of the yarn F to be wound up beingcaused by the traversing movement of the yarn traversing guide 126.

[0047] The yarn length temporarily stored in the yarn suction pipe 3 ismonitored by a yarn monitor (not shown). The reserve hoop 25 is actuatedin function of the yarn length inside the yarn suction pipe 3 andthereupon releases the piecing reserve A. This can be effected byswiveling the reserve hoop 25 or by throwing off from same in a knownmanner.

[0048] The released yarn F comes into contact with fibers that are fedto a known spinning element of the open-end spinning device 10, so thatthe spinning process can be started by renewed withdrawal of the yarn Ffrom the open-end spinning device 10. The auxiliary roller pair 24 nowdriven in draw-off direction does this.

[0049] When the piecing reserve A is released the yarn F is applied tothe draw-off shaft 110. The pressure roller 111 is now placed on thedraw-off shaft 110 so that the yarn draw-off device 11 on the machinedraws off the yarn F from the open-end spinning device 10 from then on.The auxiliary roller pair 24 is now no longer needed and for this reasonthe driven roller 241 is lifted off from the other roller 240 of theauxiliary roller pair 24.

[0050] Because of the large mass of the yarn F wound up on it, thebobbin 121 cannot be accelerated as rapidly as the pressure roller 111placed on the draw-off shaft 110, and therefore a yarn surplus iscreated between the yarn draw-off device 11 and the bobbin 121 and istaken up by the yarn suction pipe 3.

[0051] At the right moment the roller 240 also releases the yarn F in aknown manner, whereby the yarn surplus created by a shortening of thepath caused by the release of the yarn is also taken up by the yarnsuction pipe 3.

[0052] The yarn suction pipe 3 is then moved from its operating position3 b into its operating position 3 c (FIG. 1). This reduces the magnitudeof the yarn deflection. When the yarn F temporarily stored in the yarnsuction pipe 3 is used up in spite of the continuous feeding of the yarnF by the yarn draw-off device 11, the yarn path is shortened again sincethe yarn F is now applied against the yarn tension equalization hoop127.

[0053] It is possible to dispense in certain cases with an additionaloperating position 3 c when the operating position 3 b of the yarnsuction pipe 3 is properly defined for the reception of a yarn surplus.In such case a somewhat greater drop in tension, causing a certaindisturbance in the bobbin build-up must be accepted briefly for thetransfer of the yarn F to the yarn tension equalization hoop 127 as theyarn surplus stored in the yarn suction pipe 3 is used up as a result ofthe shortening of the yarn path caused thereby. For this reason morethan just one single operating position 3 b (see operating position 3 c)of the yarn suction pipe 3 is provided with the above-describedembodiment.

[0054] The yarn suction pipe 3 has taken up the yarn F in the operatingplane E_(a), has then readied it so that the reserve hoop 25 couldconstitute a piecing reserve A and has temporarily stored the yarnsurplus produced momentarily during piecing. When this temporarilystored yarn surplus has been used up, the yarn suction pipe 3 hasaccomplished its task pertaining to the piecing process and is returnedinto its rest position 3 a without having left the operating plane E_(a)during piecing.

[0055] Once all the elements and aggregates of the service unit 2 haveagain returned to their rest positions within the contours of theservice unit 2 , the service unit 2 leaves the open-end spinning device10 concerned upon successful piecing in order to work at anotheropen-end spinning device 10 now requiring service.

[0056] The service unit 2 is not only able to carry out a piecingprocess but can also replace bobbins or perform other maintenance tasks,e.g. cleaning etc.

[0057] As an example of an additional service task in which the yarnsuction pipe 3 is used, the forming of a yarn end reserve R is describedbelow. Such a yarn end reserve R is to be generated on a full bobbin 121which is to be taken from the winding device 12 and is to be replaced byan empty bobbin (see tube 125).

[0058] The operational steps up to the reception of the yarn F by theyarn suction pipe 3 are the same as described previously in connectionwith piecing. Here too the yarn suction pipe 3 takes up the yarn F foras long as the yarn suction pipe 3 is in its first operating planeE_(a), even if subsequent operational steps are carried out in a secondoperating plane E_(b).

[0059] When the yarn end which has been cut by means of the cuttingdevice assigned to the presentation device 21 is located in the yarnsuction pipe 3, driving the bobbin 121 in unwinding direction (see arrowf₃) causes a sufficient yarn length to be delivered into the yarnsuction pipe 3 for the operational steps described below, whereupon thebobbin 121 is stopped. The yarn suction pipe 3 is then moved from itsoperating plane E_(a) into another operating plane E_(b). The manner inwhich this is accomplished is explained further below.

[0060] To avoid the necessity of reserving a large area for the space tobe traversed by the yarn suction pipe 3 during this movement of the yarnsuction pipe 3 from the first operating plane E_(a) into the secondoperating plane E_(b), the rest position 3 a is provided in the closestpossible proximity of the interface S between the two operating planesE_(a) and E_(b).

[0061] When it has reached the operating plane E_(b) the yarn suctionpipe 3 is brought into a first operating position 3A before one of theends of the stopped bobbin 121. The latter is now again driven inwind-up direction (see arrow f₂), and for this is again brought intocontact with the winding roller 120. The yarn suction pipe 3 which is inoperating plane E_(b) assumes such a position in its operating position3A that the yarn F extending from the yarn suction pipe 3 to the bobbinenters neither the movement range of the yarn traversing guide 126 northe area of the yarn tension equalization hoop 127 even though thebobbin 121 is pressing on the winding roller 120. Thus parallel windingsW₁ are formed in wind-up direction (see arrow f₂) on a circumferentialarea U₁ of the bobbin body while the bobbin 121 is driven, whereby twoor three such windings W₁ suffice. The yarn suction pipe 3 is then movedbeyond the adjoining edge 128 of the bobbin 121 out of its operatingposition 3B while the bobbin 121 continues to be driven in wind-updirection. The circumferential area U₂ on which the yarn F is now woundup in order to produce a yarn end reserve R consisting of one or severalwindings is no longer within the longitudinal area of the bobbin 121 butoutside of same, in the area of tube 125. Once the desired number ofwindings of the yarn end reserve R has been formed here, the yarnsuction pipe 3 is brought into operating position 3C in thecircumferential area U₃ of the bobbin 121, where one or more parallelwindings W₂ are again produced.

[0062] As the description above shows, the yarn suction pipe 3 can bebrought into more than only one single operating position 3A, 3B or 3Calso in operating plane E_(b). Furthermore the windings W₂ can in somecases also cover the windings W₁, even though FIG. 2 shows two windingsW₁ and W₂ at two different locations of the bobbin 121, and this isachieved in that the operating positions 3A and 3C are selected so thatthey coincide.

[0063] In synchronization with the formation of the yarn end reserve R,the yarn F extending towards the yarn suction pipe 3 is cut in asuitable manner (not shown). The yarn suction pipe 3 is equipped forinstance with a cutting device at its outlet or in proximity thereof,which is able to carry out this task. Furthermore the bobbin 121 isstopped by lifting off the winding roller 120 upon formation of the yarnend reserve and the return of the yarn F on the bobbin body. The fullbobbin 121 can now be replaced by an empty tube 125.

[0064] The yarn suction pipe 3 has carried out its task and returns intoits rest position 3 a in the first operating plane E_(a). Upon thereturn of all the elements participating in the bobbin replacement or inthe formation of the yarn end reserve R into their rest positions; theservice unit 2 can leave the open-end spinning device 10 it has justserviced.

[0065] As described earlier, the bobbin 121 lies on the winding roller120 during the movement of the yarn suction pipe 3 from its operatingposition 3A into its operating position 3B. Thereby any negativeinfluence of this operational movement of the yarn suction pipe 3 uponthe already formed windings W₁ that may partially remove it is avoided.The contact position of the bobbin 121 on the winding roller 120 duringthis operational movement of the yarn suction pipe 3 therefore resultsin a defined transition of the parallel windings W₁ into the yarn endreserve R, because the yarn excursion executed in the direction of theend of tube 125 cannot affect the parallel windings W₁ beyond the nipbetween the bobbin 121 and the winding roller 120. However the contactposition of the bobbin 121 on the winding roller 120 is not absolutelynecessary for the formation of the windings W₁ themselves, so that inprinciple it suffices if the bobbin 121 is brought into contact with thewinding roller 120 only at the beginning of the above-mentioned yarnexcursion for the formation of the yarn end reserve R. On the other handhowever, the application of the full bobbin 121 on the winding roller120 causes the windings W₁ and W₂ to be rolled in to a certain degreedue to the contact pressure of the bobbin 121 on the bobbin surface, andthis is an advantage for the retention of the yarn end on the bobbin121. Added to this is the fact that the bobbin body has a certainsurface roughness because of the hairiness of the yarn F. In this mannerthe end of the yarn F deposited here in form of one or several windingsW₂ is effectively secured, even during subsequent handling in course oftransportation and further treatment in a yarn processing textilemachine, e.g. a knitting or weaving machine.

[0066] In principle it does not matter at which end of the bobbin 121the yarn end reserve R is formed. Since in subsequent further processingof the yarn F wound up on a conical bobbin 121 the yarn is pulled offfrom the bobbin on the side with the smaller diameter, it is howeveradvantageous to provide the yarn end reserve R at this bobbin end.

[0067] According to the above description the yarn suction pipe 3executes different operational movements in a defined manner in the twooperating planes E_(a) and E_(b). These operational movements of theyarn suction pipe 3 are controlled by a control device 6 that interactsalso with a transfer device 4 (see FIG. 3) by means of which the yarnsuction pipe 3 can be moved from the first operating plane E_(a) intoits second operating plane E_(b) and back. As FIG. 4 shows, the controldevice 6 can be programmed in a suitable manner. Adjusting knobs 64 areused for this for example, whereby the adjustments made can becontrolled on a display 65. In addition or alternatively, a possibilityfor the insertion of a data support (chip, CD Rom, etc) by means ofwhich the control device is suitably programmed can also be provided sothat the piecing process and other tasks can be carried out in thedesired manner during the different operational phases. In this case theyarn suction pipe 3 is brought successively into the correspondingoperating planes E_(a) and E_(b) in which it carries out thecorresponding operational movements in a predetermined time sequence byfollowing the program of the control device 6 in function of theseoperational phases.

[0068] As has been described, the yarn suction pipe 3 is brought intothe first operating plane E_(a) based on the predetermined program inorder to constitute a piecing reserve A. In this operating plane E_(a) apossibly occurring yarn surplus can also be received. To constitute ayarn end reserve R however, the control device 6, on basis of itspredetermined program, causes the yarn suction pipe 3 to be brought intoits second operating plane E_(b) in which the yarn suction pipe 3carries out the necessary operational movements.

[0069] The previously mentioned transfer device 4 (FIG. 3) has a swivelpin 40 to which the yarn suction pipe 3 is non-rotatably connected. Theswivel pin 40 is connected to a swivel drive 41 which may be designed inform of a stepping motor. This swivel drive 41 of the yarn suction pipe3 is in turn mounted on a holding device 42 which is pivotably mountedon a shaft 43. The holding device 42 is made in form of a two-arm lever,whereby a piston rod 40 of a pneumatic or hydraulic drive cylinder 44 isconnected to the free end of this lever via a coupling element 441.

[0070] The drive cylinder 44 is connected via a control valve 5controlling the arrival of the control medium into or removal of thecontrol medium out of the drive cylinder 44 to lines 50 for the arrivalor removal of the control medium. No detailed drawing of the controlvalve 5 or of the line 50 have been provided for sake of clarity, andbecause such controls are sufficiently well known.

[0071] The control valve 5 as well as the swivel drive 41 is connectedvia control lines 60 or 61 to the above-mentioned control device 6 whichcontrols the piecing process, the replacement of a full bobbin 121 by anempty tube 125 and other processes, such as e.g. cleaning of theopen-end spinning device 10 or details thereof.

[0072] As FIG. 3 clearly shows, the yarn suction pipe 3 that ispresented in FIG. 3 to the bobbin 121 (not shown) is either in theoperating plane E_(a) in which the yarn suction pipe 3 takes up the yarnF presented to it as described above and in which it also temporarilystores a yarn surplus produced during the piecing process, or it is inthe operating plane E_(b) in which the yarn suction pipe 3 presents theyarn F to the bobbin 121 so that a yarn reserve R may be produced on it,depending on the swivel position of the holding device 42. In order totransfer the yarn suction pipe 3 from the operating plane E_(a) into theoperating plane E_(b) or back, from the operating plane E_(b) into theoperating plane E_(a), the holding device 42 is swiveled correspondinglyunder the control of the control device 6, the control valve 50 and thedrive cylinder 44. Independently of the swivel position of the holdingdevice 42 and therefore of the operating plane E_(a) or operating planeE_(b) occupied by the yarn suction pipe 3, the latter is always swiveledaround the same swivel pin 40 in order to be transferred into the restposition 3 a or the operating position 3 b or 3 c or into one of theoperating positions 3A, 3B or 3C.

[0073] The described device as well as the described process are notlimited to the embodiment mentioned, but can be modified in many waysunder the present invention, in particular through the replacement ofindividual characteristics by equivalents as well as through differentcombinations of the characteristics or of their equivalents. Thus it isnot necessary for the operating planes E_(a) and E_(b) to include asharp angle α as shown in FIGS. 1 and 3. Placing the two operatingplanes E_(a) and E_(b) at different angles relative to each other isperfectly possible. Thus it is possible to bring the yarn suction pipe 3into a third operating plane (not shown) extending e.g. parallel to theplane of the drawing in addition to the two mentioned operating planesE_(a) and E_(b) in order to take over the task of the presentationdevice 21 in this third operating plane. In this third plane the yarnsuction pipe 3 can for instance take up the yarn F extending from thebobbin 121 to the suction pipe 20, e.g. through suitable control of thenegative pressures in the suction pipe 20 and in the yarn suction pipe3, and convey it to the clamping device 220 of the yarn presenter 22 aswell as to the yarn end preparation device 23. Upon release of the yarnF, the yarn suction pipe 3 can be returned from this (not shown) thirdoperating plane into its previously mentioned operating plane E_(a) tobe placed in the operating position 3 b shown in FIG. 1 where it thencarries out the described tasks.

[0074] To make it possible for the yarn suction pipe 3 to carry out thedifferent tasks and to be brought into the operating planes E_(a) andE_(b) provided for them, it may be necessary under certain conditionsthat the transfer device 4 be provided with a pin in additional to theswivel pin 40 and the pin 43.

[0075] In the embodiment described above it is also possible to transferthe yarn suction pipe 3 by means of a transfer device designed in asimilar manner as those described above through FIG. 3 from oneoperating plane E_(a), E_(b) . . . into another. For reasons of spaceavailability it is as a rule advantageous also with such a design of thedevice if the rest position 3 a of the yarn suction pipe 3 is always injust one of the operating planes E_(a), E_(b) . . . provided.

[0076] As shown in FIG. 3, the pin 43 around which the holding device 42can be swiveled is essentially parallel to the longitudinal axis of theopen-end spinning machine 1 and of its shafts, such as e.g. of thewinding roller 120 or of the draw-off shaft 110. This is especiallyadvantageous if the yarn suction pipe 3 is also to take over thetraversing of the yarn F along the bobbin 121 in addition to its storingtasks. Nevertheless it may be advantageous under certain conditions toplace the pin 43 at an angle to the longitudinal axis of the open-endspinning machine 1, e.g. in order to ensure, whatever the form of thebobbin 121 (conical or cylindrical) may be, that the yarn suction pipe 3can always be brought with its outlet 32 into the closest possibleproximity of the tube 125 and/or of the bobbin end on which the windingsW₁ and W₂ are formed.

[0077] As the embodiment of FIG. 4 shows, it is also possible to provideoperating planes E_(A) and E_(B) for the yarn suction pipe 3 which arenot at an angle α relative to each other but are parallel to each other.The yarn suction pipe 3 is for example installed non-rotatably by meansof a hub 30 on a swivel pin 70 of a transfer device 7, e.g. by means ofa hub-and-spring combination. The swivel pin 70 in the embodiment shownhas an arm 71 extending radially to the outside, to the end of which apin 72 and an intercalated coupling element 731 connects the piston rod730 of a drive cylinder 73. The control medium is conveyed to the drivecylinder 73 or is removed from it by means of lines 74, these lines 74being controlled suitably by means of a control valve 51 that isconnected via a control line 62 to the control device 6.

[0078] The hub 30 by means of which the yarn suction pipe 3 is mountedon the swivel pin 70 furthermore contains a connection bore (not shown)connected to the yarn suction pipe 3, and through it a hose 31 connectedto a negative-pressure source (not shown) or a mobile or mounted pipe isconnected to the negative-pressure source to establish the connectionbetween the yarn suction pipe 3 and the negative-pressure source. On itsouter circumference the hub 30 is provided with a circumferential groove300 into which a fork-shaped lifting element 75 enters. The end of thislifting element 75 away from the hub 30 is supported by the free end ofa piston rod 760 of a drive cylinder 76 that is connected via lines 77to the control valve 52, the latter being in turn connected via acontrol line 63 to the control device 60 for control.

[0079] With the described transfer device 7 the yarn suction pipe 3 ismoved by means of the suitably controlled drive cylinder 76 along itsswivel axis 70 into the desired operating plane E_(A) or E_(B), whilethe yarn suction pipe 3 is placed in its currently required swivelposition by means of a suitably controlled drive cylinder 73.

[0080] It goes without saying that the yarn suction pipe 3 can also beshifted between its operating planes E_(a), E_(b), . . . or E_(A), E_(B). . . by means of transfer devices that are designed differently fromthe shown embodiments (transfer device 4 or 7). It is for example alsopossible to mount the yarn suction pipe 3 in a connecting link (notshown) so that it can be shifted, whereby the connecting link may alsofollow an irregular course, depending on the tasks to be carried out bythe yarn suction pipe 3. Such a connecting link can be provided for thetransfer from one operating plane into another operating plane, as wellas for the movement of the yarn suction pipe 3 within one operatingplane. That which has been explained in connection with a connectinglink applies similarly if instead of a connecting link a curved path isprovided on which a guiding element of the yarn suction pipe 3 and/or ofthe transfer device 4 or 7 is pressed by means of an elastic or similarelement.

[0081] According to the embodiments described above the yarn F that ispresented to the yarn suction pipe 3 is taken from the bobbin 121 thatis in the winding device 12. The operational steps required to presentthe yarn F to the yarn suction pipe 3 can however deviate from theoperational steps provided for this and described above.

[0082] Nor is it an absolute necessity for the described process or forthe device used for it that the yarn F to be taken up by the yarnsuction pipe 3 is taken from bobbin 121 on the machine. The travelingservice unit 2 for example, can also carry a bobbin (not shown) fromwhich the yarn F required for piecing can be drawn off in on theoccasion of a bobbin replacement, whereby this yarn F is then presentedto the yarn suction pipe 3 in connection with these operational steps.

1. Open-end spinning device with a winding device to take up a bobbin driven by a winding roller, with a traversing guide installed within the path of the yarn before the bobbin, with a movably mounted yarn suction pipe that can be moved within a predetermined operating plane from a rest position into an operating position and back for the temporary reception of a yarn as well as with a control device controlling the movements of the yarn suction pipe, characterized in that the yarn suction pipe 3 movable within an operating plane E_(a), E_(A) can be moved into at least one additional operating plane E_(b), E_(B) and can be moved within the latter.
 2. Device as in claim 1, characterized in that at least two operating planes E_(a), E_(b) of the yarn suction pipe 3 form an angle a between them.
 3. Device as in claim 2, characterized in that the rest position 3 a of the yarn suction pipe 3 is provided in proximity of the interface S of two operating planes E_(a), E_(b) of the yarn suction pipe
 3. 4. Device as in one or several of the claims 1 to 3, characterized in that a rest position 3 a of the yarn suction pipe 3 is provided only in one single operating plane E_(a); E_(A), whatever the number of operating planes E_(a), E_(b); E_(A), E_(B) into which the yarn suction pipe 3 can be moved may be.
 5. Device as in one or several of the claims 1 to 4, characterized in that the operating positions 3 b, 3 c; 3A, 3B, 3C of the yarn suction pipe 3 which can be moved in at least two operating planes E_(a), E_(b); E_(A), E_(B) are defined in such manner that when the yarn suction pipe 3 is in its operating position 3 b, 3 c in a first operating plane E_(a), E_(A), a yarn F extending from the bobbin 121 pressing on winding roller 120 to the yarn suction pipe 3 crosses the traversing range of the yarn traversing guide 126 but is outside the traversing range of this yarn traversing guide 126 when the yarn suction pipe 3 assumes its operating position 2A, 3B, 3C in an additional operating plane E_(b), E_(a).
 6. Device as in one or several of the claims 1 to 5, characterized in that the control device 6 can be programmed in such manner that the yarn suction pipe 3 can be brought into a predetermined operating plane E_(a), E_(b); E_(A), E_(B) in function of predetermined operating phases in order to carry out different, defined operational movements in function of the occupied operating plane E_(a), E_(b); E_(A), E_(B).
 7. Device as in claims 5 and 6, characterized in that the control device 6 can be programmed in such manner that the yarn suction pipe 3 can be moved within the first operating plane E_(a), E_(A) to constitute a piecing reserve A or to take up a yarn surplus produced within the first operating plane E_(a), E_(A) and within another operating plane E_(b), E_(B) to constitute a yarn end reserve R on a full bobbin
 121. 8. Device as in one or several of the claims 1 to 7, characterized in that the yarn suction pipe 3 can be brought into more than one operating positions 3 b, 3 c; 3A, 3B, 3C within at least one of its operating planes E_(a), E_(b); E_(A), E_(B)
 9. Device as in one or several of the claims 1 to 8, characterized in that the yarn suction pipe 3 is mounted on a swivel pin
 40. 10. Device as in claim 9, characterized in that the yarn suction pipe 3 can be moved along its swivel pin
 70. 11. Device as in claim 9 or 10, characterized in that the swivel pin 40 of the yarn suction pipe 3 is in turn mounted on an additional swivel pin
 43. 12. Device as in claim 11, characterized in that the additional swivel pin 43 is essentially parallel to the axis of the winding roller
 120. 13. Process for the temporary reception of a yarn by means of a device according to one or several of the claims 1 to 12, characterized in that the yarn suction pipe 3 is sequentially brought into different operating planes in function of predetermined operating phases, in which the yarn suction pipe is imparted a defined operational movement in function of the occupied operating plane in coordination with the applicable operating phase.
 14. Process as in claim 13, characterized in that the yarn suction pipe 3 is always brought into the same operating plane to receive the yarn drawn off from a bobbin, independently of the operating plane to be occupied for the execution of certain operational movements.
 15. Process as in claim 14, characterized in that in order to constitute a piecing reserve the yarn suction pipe is imparted an operational movement in the operating plane in which the yarn suction pipe has previously taken up the yarn drawn off from a bobbin.
 16. Process as in claim 14 or 15, characterized in that in order to take up a yarn surplus produced during piecing, the yarn suction pipe is imparted its operational movements in the operating plane in which the yarn suction pipe has previously taken up the yarn drawn off from the bobbin.
 17. Process as in one or several of the claims 14 to 16, characterized in that in order to constitute a yarn end reserve on the full bobbin, the yarn suction pipe is transferred from the operating plane in which it has previously taken up the yarn drawn off from a bobbin into another operating plane in which it is imparted its operational movements.
 18. Process as in claim 17, characterized in that the yarn presents itself to the yarn suction pipe located in its first operating plane, in that the full bobbin lifted up from the winding roller is then rotated in unwinding direction and takes up this released yarn length, in that the bobbin is then stopped, the yarn suction pipe is moved into another operating plane and is moved within this additional operating plane in front of one end of the stopped bobbin, in that the bobbin is then applied to the winding roller and is driven in wind-up direction in order to constitute one or several parallel windings, in that the yarn suction pipe is moved beyond the adjoining edge of the bobbin and into the area of the tube extending axially beyond the bobbin where also one or several windings are made, whereupon the yarn suction pipe returns into the area of the windings formed previously at the bobbin end in order to form again one or several windings, whereupon the bobbin is stopped by being lifted from the winding roller, the yarn extending from the bobbin to the yarn suction pipe is cut and the yarn suction pipe is moved back into its starting position within the first operating plane. 